skia2/gm/lighting.cpp

/*
 * Copyright 2012 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */

#include "gm.h"
#include "SkLightingImageFilter.h"
#include "SkOffsetImageFilter.h"
#include "SkPoint3.h"

#define WIDTH 330
#define HEIGHT 660

namespace skiagm {

class ImageLightingGM : public GM {
public:
    ImageLightingGM() : fInitialized(false) {
        this->setBGColor(0xFF000000);
    }

protected:

    SkString onShortName() override {
        return SkString("lighting");
    }

    void make_bitmap() {
        fBitmap.allocN32Pixels(100, 100);
        SkCanvas canvas(fBitmap);
        canvas.clear(0x00000000);
        SkPaint paint;
        paint.setAntiAlias(true);
        sk_tool_utils::set_portable_typeface(&paint);
        paint.setColor(0xFFFFFFFF);
        paint.setTextSize(SkIntToScalar(96));
        const char* str = "e";
        canvas.drawText(str, strlen(str), SkIntToScalar(20), SkIntToScalar(70), paint);
    }

    SkISize onISize() override {
        return SkISize::Make(WIDTH, HEIGHT);
    }

    void drawClippedBitmap(SkCanvas* canvas, const SkPaint& paint, int x, int y) {
        canvas->save();
        canvas->translate(SkIntToScalar(x), SkIntToScalar(y));
        canvas->clipRect(SkRect::MakeWH(
          SkIntToScalar(fBitmap.width()), SkIntToScalar(fBitmap.height())));
        canvas->drawBitmap(fBitmap, 0, 0, &paint);
        canvas->restore();
    }

    void onDraw(SkCanvas* canvas) override {
        if (!fInitialized) {
            make_bitmap();
            fInitialized = true;
        }
        canvas->clear(0xFF101010);
        SkPaint checkPaint;
        checkPaint.setColor(0xFF202020);
        for (int y = 0; y < HEIGHT; y += 16) {
          for (int x = 0; x < WIDTH; x += 16) {
            canvas->save();
            canvas->translate(SkIntToScalar(x), SkIntToScalar(y));
            canvas->drawRect(SkRect::MakeXYWH(8, 0, 8, 8), checkPaint);
            canvas->drawRect(SkRect::MakeXYWH(0, 8, 8, 8), checkPaint);
            canvas->restore();
          }
        }
        SkPoint3 pointLocation = SkPoint3::Make(0, 0, SkIntToScalar(10));
        SkScalar azimuthRad = SkDegreesToRadians(SkIntToScalar(225));
        SkScalar elevationRad = SkDegreesToRadians(SkIntToScalar(5));
        SkPoint3 distantDirection = SkPoint3::Make(SkScalarMul(SkScalarCos(azimuthRad),
                                                               SkScalarCos(elevationRad)),
                                                   SkScalarMul(SkScalarSin(azimuthRad),
                                                               SkScalarCos(elevationRad)),
                                                   SkScalarSin(elevationRad));
        SkPoint3 spotLocation = SkPoint3::Make(SkIntToScalar(-10),
                                               SkIntToScalar(-10),
                                               SkIntToScalar(20));
        SkPoint3 spotTarget = SkPoint3::Make(SkIntToScalar(40), SkIntToScalar(40), 0);
        SkScalar spotExponent = SK_Scalar1;
        SkScalar cutoffAngle = SkIntToScalar(15);
        SkScalar kd = SkIntToScalar(2);
        SkScalar ks = SkIntToScalar(1);
        SkScalar shininess = SkIntToScalar(8);
        SkScalar surfaceScale = SkIntToScalar(1);
        SkColor white(0xFFFFFFFF);
        SkPaint paint;

        SkImageFilter::CropRect cropRect(SkRect::MakeXYWH(20, 10, 60, 65));
        SkImageFilter::CropRect fullSizeCropRect(SkRect::MakeXYWH(0, 0, 100, 100));
        SkAutoTUnref<SkImageFilter> noopCropped(SkOffsetImageFilter::Create(0, 0, NULL, &cropRect));

        int y = 0;
        for (int i = 0; i < 3; i++) {
            const SkImageFilter::CropRect* cr = (i == 1) ? &cropRect : (i == 2) ? &fullSizeCropRect : NULL;
            SkImageFilter* input = (i == 2) ? noopCropped.get() : NULL;
            paint.setImageFilter(SkLightingImageFilter::CreatePointLitDiffuse(pointLocation,
                                                                              white,
                                                                              surfaceScale,
                                                                              kd,
                                                                              input,
                                                                              cr))->unref();
            drawClippedBitmap(canvas, paint, 0, y);

            paint.setImageFilter(SkLightingImageFilter::CreateDistantLitDiffuse(distantDirection,
                                                                                white,
                                                                                surfaceScale,
                                                                                kd,
                                                                                input,
                                                                                cr))->unref();
            drawClippedBitmap(canvas, paint, 110, y);

            paint.setImageFilter(SkLightingImageFilter::CreateSpotLitDiffuse(spotLocation,
                                                                             spotTarget,
                                                                             spotExponent,
                                                                             cutoffAngle,
                                                                             white,
                                                                             surfaceScale,
                                                                             kd,
                                                                             input,
                                                                             cr))->unref();
            drawClippedBitmap(canvas, paint, 220, y);

            y += 110;

            paint.setImageFilter(SkLightingImageFilter::CreatePointLitSpecular(pointLocation,
                                                                               white,
                                                                               surfaceScale,
                                                                               ks,
                                                                               shininess,
                                                                               input,
                                                                               cr))->unref();
            drawClippedBitmap(canvas, paint, 0, y);

            paint.setImageFilter(SkLightingImageFilter::CreateDistantLitSpecular(distantDirection,
                                                                                 white,
                                                                                 surfaceScale,
                                                                                 ks,
                                                                                 shininess,
                                                                                 input,
                                                                                 cr))->unref();
            drawClippedBitmap(canvas, paint, 110, y);

            paint.setImageFilter(SkLightingImageFilter::CreateSpotLitSpecular(spotLocation,
                                                                              spotTarget,
                                                                              spotExponent,
                                                                              cutoffAngle,
                                                                              white,
                                                                              surfaceScale,
                                                                              ks,
                                                                              shininess,
                                                                              input,
                                                                              cr))->unref();
            drawClippedBitmap(canvas, paint, 220, y);

            y += 110;
        }
    }

private:
    typedef GM INHERITED;
    SkBitmap fBitmap;
    bool fInitialized;
};

//////////////////////////////////////////////////////////////////////////////

static GM* MyFactory(void*) { return new ImageLightingGM; }
static GMRegistry reg(MyFactory);

}